When working with conventional nail drivers, centre punches, mandrels and similar tools, intended for striking with a hammer, and when nailing various types of cable clips etc., one is confronted with a number of problems:
Limited access. PA1 The tool (or the clip, the nail etc.) can only be held in a thumb grip. PA1 The hand blocks the view of the tool and/or the object to be driven in and precision is impaired. PA1 The lack of view and the instability of the tool make it easy to cause impact damage on the hand and on the object. PA1 Stressing of hand muscles may--during prolonged work--cause occupational injuries. PA1 By e.g. nail-drivers, centre-punches and other applications, each tool can only handle a very limited range of dimensions. PA1 Problems are encountered in equipping oneself with, and looking after, a complete tool kit for a certain work assignment at hand, due to the many separate tools.
Some attempts have been made before to improve the situation. GB 2 171 343 A shows a centre punch mounted in a transversal bar that can be used as a handle for the centre punch, but the handle at the same time functions as a chuck wrench and is not very ergonomically shaped.
Also U.S. Pat. No. 640 696 shows a device where a centre punch or chaser punch has been equipped with a side handle. This tool is however shaped for one single, special purpose and solves very few of the problems listed above.
Furthermore, through DE B 1 226 247 a hand-held tool is known, having exchangeable tool bits attached in a fixed position at approximately right angles to the longitudinal axis of the handle. This device is however only intended for nail countersinking and is not equipped for universal use. Access is limited by all the nail drivers being attached at a fixed angle relative to the handle. Furthermore, only one nail driver at a time can be in a working position, which entails many manual operations when performing work where several sizes are needed. Finally, the device, due to it's design, can only be equipped with exchangeable tool bits having a working tip diameter that is smaller than their handle attachment end diameter.